Safety device for revolving platforms



Oct. 20, 1925- 1,557,632

J. H. TRESIDER ET AL SAFETY DEVICE FOR REVOLVING PLATFORIS Filed July 17. 1925 2 Sheets-Sheet l Oct. 20,1925- 1,557,632 I J. H. TRESIDER ET AL SAFETY DEVICE FOR REVOLVING iLATFORIS Filed July 17. 1925 2 Sheets-Sheet 2 Patented Oct. 29, 1925.

UNITED STATES PATENT OFFICE.

JOHN H. TEESIDER, OF CHISHOLM,.A.ND CLARENCE M. BO SS, OF DULUTH, MINNESOTA.

.sarnrx nnvIca roa auvo vme PLATFORMS.

Application fi1ed July 17, 1925. Serial No. 44,411.

To all whom it may concern. I

Be it known that we, J OHN H. TRESIDER and CLARENCE M. Boss, citizens of the United States, residents, respectively, of Chisholm, in the county of St. Louis and State of Minnesota, and of Duluth, in the county of St. Louis and State of Minnesota, have jointly invented certain new and use ful Improvements in Safety Devices for Revolving Platforms, of which the following is a specification.

This invention relates to a new and improved safety device for revolving platforms and more particularly, to a guard arrangement automatically moving with av movable platform to enclose the danger zone of such movement. WVith types of apparatus, such as steam shovels, locomotive cranes or the like, which include a rotating platform supported upon a fixed platform, there is danger to personnel working about the apparatus when the revolving platform is rotated during its operation. At certain points of its swinging movement the platformwill form an acute angle with the fixed platform and persons caught in such angles may be seriously injured.

It is an object of the present invention to provide a new and improved device adapted to define the danger zone in movement of platforms and to thereby warn personnel of danger.

It is an additional object to provide a construction of this character which is simple in design and construction and which may be added to existing apparatus without alteration therein.

Other and further objects will appear as the description proceeds.

e have illustrated our invention some what diagrammatically in the accompanying drawings, in which- Figure 1 is a plan view showing the device applied to a car;

Figure 2 is a side elevation of Figure 1, and

Figure 3 is an end elevation of Figure 1.

The apparatus to which our invention is applied comprises the car or fixed platform 11 supported on the wheels 12. The movable platform 13 is pivotally supported on the fixed platform 11 and adapted to swing about P VQt 14. This swinging platform may support a steam shovel, or crane, or any type of apparatus and may be rotated by any form of mechanism, These details form s me ofthe present invention and have 'not; been shown. y

I The guard cables 15 pass a'roundthe pul leys. 16 located at the corners of the fixed platform and pass over the pulleys 17 into the guide tubes 18. Each end of the cable is provided with a weight 19 freely movable in a guide tube 18. The rollers 20 ex tend from the lower face of the movable platform 13 and into the path of the cables 15.

When the movable platform 13 is swung to either side, the corresponding roller 20 engages the adjacent cable 15 and swings it out as clearly shown in broken lines in Figure 1. This movement of the cable is permitted by the lengths of the ends of the cable extending into the guide tubes 18. Excess length of cable is had such that the revolving platform may be completely rotated without pulling the weights'19 out of the guide tubes 18. The weights 19 are sufficient to take up any slack and will retain the cable taut as indicated in Figure 1.

These guard cables serve to clearly indicate to personnel working about the apparatus the danger zone as the revolving platform swings and will prevent men from be ing caught between the movable and fixed platforms.

We have shown one preferred form by wa I of illustration, but we contemplate suc changes and modifications as come within the spirit and scope of the accompanying claims.

We claim:

1. In a safety device for movable platforms, a fixed platform, a guard member carried by the fixed platform, and means carried by the movable platform and adapted to engage the guard member when the movable platform extends beyond the fixed platform.

2. In a safety device for movable platforms, a fixed platform, a flexible guard member carried by the fixed platform, and rollers carried by the movable platform and adapted to engage the guard member when the movable platform extends beyond the fixed platform.

3. In a safety device for movable platforms, a fixed platform, a guard cable carried by the fixed platform, under yielding tension, and means carried by the movable platform and adapted to an age the guard ble nd e t nd it r es he fi e P t form when the movable platform extends beyond the fixed platform.

4. In a safety device for movable platfor-ms a fix-ed platform, a guard cable passing about pulleys on the fixed platform, Weights secured to the ends of the cable to put it under tension and means carried by the movable platform andadapted-to en gage the guard cable and extend it beyond the fixed platform when the movable platform extends beyond the fixed platform.

5. a safety device for movable platforms, a fixed platform, a guard cable passing about pulleys on the fixed plat-form, Weights secured to the ends of the cable to put it under tension, vertical guide tubes housing said Weights, and means carried by the movable platform and adapted to engage the guard cable and extend it beyond the fixed platform when the movable plat form extends beyond the fixed platform.

Signed at Hibbing, Minnesota, this 30th day of June, 1925.

JOHN H. TRESIDER, CLARENCE M. BOSS. 

